Water Treatment Plant

Construction is underway to upgrade the Lake Oswego Tigard Water Treatment Plant (WTP) located in West Linn. Lake Oswego’s original water treatment plant was constructed in this location in 1968, in what was then unincorporated Clackamas County. The facility has treated Clackamas River water to high-quality drinking water standards for almost 50 years.

Lake Oswego’s source of water originates in the Clackamas River watershed. This high-quality water source receives runoff and snowmelt from a 940 square mile area located on the western slopes of Ollalie Butte, near Timothy Lake, in the Mount Hood National Forest.

As part of the Lake Oswego Tigard Water Partnership project, Lake Oswego’s water system has been undergoing many changes and upgrades, including the water treatment process. The current treatment process, placed online in spring 2016, is conventional treatment using ballasted flocculation and granular activated carbon filtration.

We want you to know...

Lake Oswego has reduced paper use by providing the 2016 Annual Water Quality Report online. Cities are no longer required to send the reports in the mail. It is a great choice for everyone, and the planet.

During an emergency, such as a major earthquake, the City of Lake Oswego may issue a "boil water notice" until it can verify that the water is not contaminated and is safe to drink. During a "boil water notice" period, any water used for drinking or food preparation should be boiled at a full rolling boil for at least one full minute.

On April 11, 2008, the Oregon Water Resources Department issued a Final Order approving the City of Lake Oswego’s first Water Management and Conservation Plan (WMCP or “Plan”). The purpose of the Plan is to guide the development, financing and implementation of water management and conservation programs and policies to ensure sustainable use, without waste, of publicly...

The City of Lake Oswego is requesting volunteers to assist with a sampling program to collect samples of household drinking water to be analyzed for lead and copper. Sixty household sampling sites will be asked to sample once before the end of 2013 and again in the first six months of 2014.